[docs]classAskInfinitesimalHandler(CommonHandler):""" Handler for key 'infinitesimal' Test that a given expression is equivalent to an infinitesimal number """@staticmethoddef_number(expr,assumptions):# helper methodreturnexpr.evalf()==0@staticmethoddefBasic(expr,assumptions):ifexpr.is_number:returnAskInfinitesimalHandler._number(expr,assumptions)@staticmethod